Destroying the current window and create a new one - c

Question

I have a program that is written in WinAPI.
I have the Login Window, and after that, the actual program window.
I want to destroy the login window, and create the new window..
I've been using this :
Destroying the program :
DestroyWindow(MainHwnd);
and the WndProc of the window (of MainHwnd's window):
LRESULT Client::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CREATE:
break;
case WM_COMMAND:
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(1);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
And the people here in StackOverflow told me in my previous question, that I a'int destroying the window currently, and I'm causing a Stack Overflow which ends where the window is destroyed (the program stills run - so it looks like everything is working as planed), but I do not want to use bad programing (specialy causing stack overflow to destroy a window haha)
So, how can I destroy a window correctly?
Also, some times, when I use DestroyWindow(MainHwnd) it gets inside both WM_DESTROY and WM_CLOSE (in the current WndProc I have posted above).. Is this related to the Stack Overflow problem ?
Btw - I also know how to use Windows Forms in #C, I'm trying to write something like :
this.Close(); which closes the current window (maybe that makes my question more clear)...
Thanks!

Answer 1

From microsoft about the WM_CLOSE:
An application can prompt the user for confirmation, prior to destroying a window, by processing the WM_CLOSE message and calling the DestroyWindow function only if the user confirms the choice. By default, the DefWindowProc function calls the DestroyWindow function to destroy the window.
So calling DestroyWindow(hwnd); or not is the same.
LRESULT Client::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CREATE:
break;
case WM_COMMAND:
break;
case WM_CLOSE:
//DestroyWindow(hwnd);
break;
or
case WM_CLOSE:
DestroyWindow(hwnd);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
see an example closing window
Basically is what i said.
valter